* <<F83.1370>> Chord Keying

With eight primary keys, there are:
1 0-key combinations
8 1-key combinations
28 2-key combinations
56 3-key combinations
70 4-key combinations
56 5-key combinations
28 6-key combinations
8 7-key combinations
1 8-key combinations

Because there are only four fingers for keying, we can discard the 
idea of actually keying the 5, 6, 7, and 8-key combinations.  
However, we can still use those additional 93 key patterns by using a 
bit-flip thumbswitch, so that the operator would key the inverse of 
the pattern 

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Excerpted from:

PUBLIC NOTES (F)
http://alph.laemeur.com/txt/PUBNOTES-F
©2015 Adam C. Moore (LÆMEUR) <adam@laemeur.com>